The major objective of this research proposal is to determine the biochemical characteristics and covalent structure of basement membrane collagens from normal and diabetic human kidney. Kidneys will be obtained at the time of autopsy. At the present time many conflicting views exist concerning the molecular organization of basement membrane collagens. During the primary stages of this investigation the work will be directed towards determining the biochemical characteristics of the different alpha chains in glomerular basement membrane with regards to their molecular weight, and amino acid and carbohydrate composition. The lysine and hydroxylysine-derived crosslinks will be quantitated and characterized. As investigations proceed the CNBr-peptides will be prepared from the various alpha chains and will be characterized by amino acid and carbohydrate composition with current available methodology. The amino acid sequence of these peptides will be determined in order to obtain the complete covalent structure of the alpha chains. Collagen is one of the major component of glomerular basement membrane. A definitive understanding of its chemical structure is essential in formulating its function in the normal and diabetic kidney will provide basic information at the molecular levle with could lead to a better understanding of the involvement of collagen in Diabetes Mellitus.